fix a few linux compilation warnings

core/src/fpdfapi/fpdf_parser/fpdf_parser_decode.cpp

 // Copyright 2014 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #include "../../../include/fpdfapi/fpdf_parser.h"
 #include "../../../include/fpdfapi/fpdf_module.h"
 #include "../../../include/fxcodec/fx_codec.h"
 #include <limits.h>
@@ skipping 220 matching lines @@
     check *= BitsPerComponent;
     if (check > INT_MAX - 7) {
         return FALSE;
     }
     return TRUE;
 }
 ICodec_ScanlineDecoder* FPDFAPI_CreateFlateDecoder(FX_LPCBYTE src_buf, FX_DWORD src_size, int width, int height,
         int nComps, int bpc, const CPDF_Dictionary* pParams)
 {
     int predictor = 0;
+    // TODO(tsepez): bEarlyChange not use, also BPC vs. bits per component?

[jun_fang, 2015/01/16 22:07:58]

We think that bEarlyChange can be removed. The history is lost and we just guess
it shall be updated but not when code was changed for fixing bugs in this
function. bpc and BitsPerComponen are still used.

     FX_BOOL bEarlyChange = TRUE;
     int Colors = 0, BitsPerComponent = 0, Columns = 0;
     if (pParams) {
         predictor = ((CPDF_Dictionary*)pParams)->GetInteger(FX_BSTRC("Predictor"));
         bEarlyChange = ((CPDF_Dictionary*)pParams)->GetInteger(FX_BSTRC("EarlyChange"), 1);
         Colors = pParams->GetInteger(FX_BSTRC("Colors"), 1);
         BitsPerComponent = pParams->GetInteger(FX_BSTRC("BitsPerComponent"), 8);
         Columns = pParams->GetInteger(FX_BSTRC("Columns"), 1);
         if (!CheckFlateDecodeParams(Colors, BitsPerComponent, Columns)) {
             return NULL;
@@ skipping 280 matching lines @@
     }
 }
 FX_DWORD FlateDecode(const FX_BYTE* src_buf, FX_DWORD src_size, FX_LPBYTE& dest_buf, FX_DWORD& dest_size)
 {
     CCodec_ModuleMgr* pEncoders = CPDF_ModuleMgr::Get()->GetCodecModule();
     if (pEncoders) {
         return pEncoders->GetFlateModule()->FlateOrLZWDecode(FALSE, src_buf, src_size, FALSE, 0, 0, 0, 0, 0, dest_buf, dest_size);
     }
     return 0;
 }